1. Field of the Invention
The present invention relates to a display control system advantageously applicable to a notebook type personal computer, word processor or similar small size electronic apparatus requiring a power saving implementation. More particularly, the present invention is concerned with a display control system operable with a minimum of power to extend the continuous operation time of the apparatus.
2. Description of the Background
A personal computer or a word processor, for example, can be powered by a battery and should preferably be operable continuously over a long period of time, particularly, a notebook type personal computer is equivalent in performance and function to a desk-top type personal computer and can be powered by a battery. However, the problem is that the continuous operation time of the personal computer is limited by the capacity of the battery and, therefore, cannot operate continuously over a sufficiently long period of time. Further, there is an increasing demand for electronic apparatuses, whether they be powered by a battery or not, having a power saving configuration. Regarding a display, various power saving implementations have also been proposed in the past. For example, Japanese Patent Laid-Open Publication (Kokai) No. 59-2081 teaches a drive circuit applicable to a plasma display panel which is capable of displaying data in a plurality of modes, e.g., a segment display mode and a dot matrix display mode and effects each of such modes with a particular drive circuit. The drive circuit disclosed in this Laid-Open Publication interrupts power supply to, among the drive circuits, one assigned to the display mode not used and one assigned the display mode held in a blanking state. Japanese Patent Laid-Open Publication No. 3-105561 discloses a word processor which senses data appearing in a picture and implements both the anti-deterioration of the display and the power saving effect by combining the fall of brightness and the shut-off of power supply.
However, the prior art implementations are not fully satisfactory in respect of power saving.